size_t Database::LoadFromTextFile( std::istream &is)
{
is.unsetf(std::ios_base::skipws);
zones.clear();
char c=0;
while( is && !is.eof() )
{
q_zone z_temp(is, c);
if (z_temp.size()==0)
{
ErrorInZone(zones.size());
}
zones.push_back(z_temp);
is >> c;
if (is)
{
switch (c)
{
case '\n':
c = 0;
break;
default:
c = atoi(&c);
is.get();
break;
}
}
}
return zones.size();
}
// Détermine les descripteurs de Fourier d'un contour
std::vector<std::complex<double>> descripteur_fourier_normal (std::vector< std::vector<cv::Point> > contour, int c_max) {
int c_min = -c_max;
int length = contour[0].size();
double x_moy, y_moy;
for (auto& pt : contour[0]) {
x_moy += pt.x;
y_moy += pt.y;
}
x_moy = x_moy / (length);
y_moy = y_moy / (length);
std::complex<double> z_moy(x_moy, y_moy);
std::vector<std::complex<double>> serie;
std::vector<std::complex<double>> spectre;
for (auto& pt : contour[0]) {
std::complex<double> z_temp(pt.x, pt.y);
z_temp = z_temp - z_moy;
serie.push_back(z_temp);
}
cv::dft(serie, spectre,cv::DFT_SCALE + cv::DFT_COMPLEX_OUTPUT);
std::vector<std::complex<double>> coeff;
for (int i = 0; i < c_max; ++i) {
coeff.push_back(spectre[i + spectre.size() - c_max]);
}
for (int i = 0; i < c_max + 1; ++i) {
coeff.push_back(spectre[i]);
}
if (std::abs(coeff[c_max - 1]) > std::abs(coeff[c_max + 1])) {
std::reverse(coeff.begin(), coeff.end());
}
double phi = std::arg(coeff[c_max - 1] * coeff[c_max + 1]) / 2.0;
for (auto& i : coeff) {
i = i * std::polar ((double) 1.0, -phi);
}
double theta = std::arg(coeff[c_max + 1]);
for (int k = c_min; k <= c_max; ++k) {
coeff[k+c_max] = coeff[k+c_max] * std::polar((double) 1.0, (double) (-k) * theta);
}
double module = std::abs(coeff[c_max + 1]);
// Normalisation
for (auto& value : coeff) {
value = value / module;
}
return coeff;
}